Forecasting future states of a multi-active cloud system

ABSTRACT

An embodiment of the invention may include a method, computer program product and computer system for forecasting future states of a multi-active cloud. The method, computer program product and computer system may include a computing device that determines the operating state of the passive server. The operating state of the passive server is one or more of a deploying state and a smoke testing state. The computing device may determine the probability of the operating state successfully completing. The computing device may delay the second asynchronous workflow until the operating state successfully completes based on the probability of the operating state successfully completing exceeding a predetermined value.

BACKGROUND

The present invention relates to states of a multi-active cloud system,and more particularly to forecasting future states of a multi-activecloud system.

Cloud systems can be very complex distributed systems. In larger cloudsystems, there may be many types of nodes, containing code from variousdevelopment teams, deployed by a different operations teams with manytest teams responsible for testing different parts of the system. Cloudemphasizes concepts such as self-service, the Application ProgrammingInterface (API) economy and automation. The API economy is thecommercial exchange of business functions, capabilities, or competenciesas services using web application programming interfaces (APIs). Bearingthis in mind, an idealized system includes a fully automated deploymentand testing process.

Consider an active-active or active-passive Software as a Service (SaaS)deployment architecture, whereby new code is deployed in parallel toexisting code and end users are eventually “flipped” from the old activeside to a new active side. Requests received from an end user are routedthrough load balancing so that the end user is not aware of which of thetwo sides is providing the service. This fully automated solutionintroduces challenges. It is desirable that test automation executewithout manual intervention but there may be little purpose in startinga test run just before a code “flip” occurs. In an active-passivedeployment, the flip may cause an outage causing the test to fail and inan active-active deployment, it may be more desirable to wait untilafter a flip so that the test run executes against the most up to datecode level.

It would be desirable to track the various states of cloud environmentsand publish this information, for programmatically knowing the currentstate of an environment, such as whether it is available. It would alsobe desirable to publish this information to provide indications offuture states, for example, if a code flip will likely occur in 20minutes, it may be best to delay a test run until the flip is complete.

BRIEF SUMMARY

An embodiment of the invention may include a method, computer programproduct and computer system for forecasting future states of amulti-active cloud. The method, computer program product and computersystem may include a computing device that determines the operatingstate of the passive server. The operating state of the passive serveris one or more of a deploying state and a smoke testing state. Thecomputing device may determine the probability of the operating statesuccessfully completing. The computing device may delay the secondasynchronous workflow until the operating state successfully completesbased on the probability of the operating state successfully completingexceeding a predetermined value.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be described inmore detail, by way of example only, with reference to the accompanyingdrawings, in which:

FIG. 1 depicts a cloud computing node according to an embodiment of thepresent invention;

FIG. 2 depicts a cloud computing environment according to an embodimentof the present invention;

FIG. 3 depicts abstraction model layers according to an embodiment ofthe present invention;

FIG. 4 is a state diagram of the states of a system in a multi-activecloud system;

FIG. 5 is a block diagram of an embodiment of a system of forecastingfuture states of the multi-active cloud system of FIG. 4 ;

FIG. 6 is a data flow diagram showing data flows in an active/passivecloud system; and

FIG. 7 is a flow diagram of an embodiment of a method of forecastingfuture states of the multi-active cloud system of FIG. 4 .

DETAILED DESCRIPTION

Embodiments of the present invention will now be described in detailwith reference to the accompanying Figures.

It is understood in advance that although this disclosure includes adetailed description of cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded, automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active consumer accounts). Resource usage canbe monitored, controlled, and reported providing transparency for boththe provider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based email). Theconsumer does not manage or control the underlying cloud infrastructureincluding network, servers, operating systems, storage, or evenindividual application capabilities, with the possible exception oflimited consumer-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication-hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting forload-balancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 1 , a schematic of an example of a cloud computingnode is shown. Cloud computing node 110 is only one example of asuitable cloud computing node and is not intended to suggest anylimitation as to the scope of use or functionality of embodiments of theinvention described herein. Regardless, cloud computing node 110 iscapable of being implemented and/or performing any of the functionalityset forth hereinabove.

In cloud computing node 110, there is a computer system/server 112,which is operational with numerous other general purpose or specialpurpose computing system environments or configurations. Examples ofwell-known computing systems, environments, and/or configurations thatmay be suitable for use with computer system/server 112 include, but arenot limited to, personal computer systems, server computer systems, thinclients, thick clients, hand-held or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 112 may be described in the general context ofcomputer system-executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 112 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 1 , computer system/server 112 in cloud computing node110 is shown in the form of a general purpose computing device. Thecomponents of computer system/server 112 may include, but are notlimited to, one or more processors or processing units 116, a systemmemory 128, and a bus 118 that couples various system componentsincluding system memory 128 to processor 116.

Bus 118 represents one or more of any of several types of busstructures, including a memory bus or memory controller, a peripheralbus, an accelerated graphics port, and a processor or local bus usingany of a variety of bus architectures. By way of example, and notlimitation, such architectures include Industry Standard Architecture(ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA)bus, Video Electronics Standards Association (VESA) local bus, andPeripheral Component Interconnects (PCI) bus.

Computer system/server 112 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 112, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 128 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 130 and/or cachememory 132. Computer system/server 112 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 134 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM, or other optical media can be provided.In such instances, each can be connected to bus 118 by one or more datamedia interfaces. As will be further depicted and described below,memory 128 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

Program/utility 140, having a set (at least one) of program modules 142,may be stored in memory 128 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating systems, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 142 generally carry out the functionsand/or methodologies of embodiments of the invention as describedherein.

Computer system/server 112 may also communicate with one or moreexternal devices 114 such as a keyboard, a pointing device, a display124, etc.; one or more devices that enable a consumer to interact withcomputer system/server 112; and/or any devices (e.g., network card,modem, etc.) that enable computer system/server 112 to communicate withone or more other computing devices. Such communication can occur viaI/O interfaces 122. Still yet, computer system/server 112 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 120. As depicted, network adapter 120communicates with the other components of computer system/server 112 viabus 118. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 112. Examples include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

Referring now to FIG. 2 , illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 comprises one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 54B, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 1 are intended to be illustrative only and that computing nodes10 and cloud computing environment 50 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 3 , a set of functional abstraction layersprovided by cloud computing environment 50 (FIG. 1 ) is shown. It shouldbe understood in advance that the components, layers, and functionsshown in FIG. 2 are intended to be illustrative only and embodiments ofthe invention are not limited thereto. As depicted, the following layersand corresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include: mainframes 61; RISC(Reduced Instruction Set Computer) architecture based servers 62;servers 63; blade servers 64; storage devices 65; and networks andnetworking components 66. In some embodiments, software componentsinclude network application server software 67 and database software 68.

Virtualization layer 70 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers71; virtual storage 72; virtual networks 73, including virtual privatenetworks; virtual applications and operating systems 74; and virtualclients 75.

In one example, management layer 80 may provide the functions describedbelow. Resource provisioning 81 provides dynamic procurement ofcomputing resources and other resources that are utilized to performtasks within the cloud computing environment. Metering and Pricing 82provide cost tracking as resources are utilized within the cloudcomputing environment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal 83 provides access to the cloud computing environment forconsumers and system administrators. Service level management 84provides cloud computing resource allocation and management such thatrequired service levels are met. Service Level Agreement (SLA) planningand fulfillment 85 provide pre-arrangement for, and procurement of,cloud computing resources for which a future requirement is anticipatedin accordance with an SLA.

Workloads layer 90 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation 91; software development and lifecycle management 92; virtualclassroom education delivery 93; data analytics processing 94;transaction processing 95 and cost generation 96. As mentioned above,all of the foregoing examples described with respect to FIG. 3 areillustrative only, and the invention is not limited to these examples.

Embodiments of the present invention provide a system capable ofaggregating and providing the state of a cloud SaaS deployment systemwith sufficient detail to enable forecasting or prediction of futurestates. The specific embodiment described below is a system state thatidentifies a current “passive side” software upgrade with a potentialimminent future “switch” between the “active” side and the “passive”side of an environment. For example, in an active/passive deploymentarchitecture, new code may be deployed to an passive side of anenvironment which is then switched out with the current active side.Users are re-directed from between sides and the code upgrade is exposedto end users. This forecasting of a future state allows, for example,test automation to decide the best course of action in terms of “kickoff testing now” or “wait until code upgrade before testing”.

FIG. 4 is a state diagram of the states of a system in a multi-activecloud system. The states are those which a distributed system in anactive/passive deployment architecture may pass through. In thisexemplary embodiment, there is always a first “active” side of theenvironment in the “Available” state 416. A second “passive” side movesthrough the other states in FIG. 4 , trying to get into a healthy stateto eventually “flip” and replace the old first “active” side.

The second “passive” side may be in a Decommissioned state 402 andprepared for a deployment of new code to that side. From theDecommissioned state 402, deployment starts for the second “passive”side and the state of that side moves to a Deploying state 404. When thesecond “passive” side is in the Deploying state 404, any test automationshould not try to start any testing on the second “passive” side as itis being upgraded with new code. Any testing that is started when in theDeploying state 404 is liable to fail because there will be an outagewhen end users are “flipped” from the first previously active side tothe second previously passive side when it flips to be active.

If the deployment to the second passive side is unsuccessful, then thestate changes to a Deploy Failed state 406 and when deployment isretried, the state returns to a Deploying state 404. If the deploymentis successful, then the state changes to a Smoke Test Running state 408.A Smoke Test is a short set of tests run on each new build of code toverify that the build is testable before the build is released into thehands of the test team. The set of tests exercise the mainstreamfunctionality of the application software. If the Smoke Test isunsuccessful, then the state changes to a Smoke Test Failed state 410and then back to a Deploying state 404. If the Smoke Test is successful,then the state changes to a Flipping state 412. When the second“passive” side is in the Smoke Test Running state 408, any testautomation should not try to start any testing on the second “passive”side as it is being upgraded with new code. Any testing that is startedwhen in the Smoke Test Running state 408 is liable to fail because therewill be an outage when end users are “flipped” from the first previouslyactive side to the second previously passive side when it flips to beactive.

When the state changes to a Flipping state 412, any test automationknows that it should not try to start any testing on the second“passive” side as it is in the process of being flipped. Any testingthat is started when in the Flipping state 412 will fail because therewill be an outage when end users are “flipped” from the first previouslyactive side to the second previously passive side when it flips to beactive. The test automation also knows that the active side code levelwill be upgraded shortly.

If the flipping between the second passive and the first active sidefails, then the second passive side changes to a Flip Failed state 414and then to a Flipping state 418 as it is flipped back to being apassive side. From a Flipping state 418, it returns to a Decommissionedstate 402 and the code deployment may be retried.

At the Deploying state 404, the Smoke Test Running state 408 and theFlipping state 412, as mentioned above, any test automation should nottry to start any testing on the second “passive” side as it is beingupgraded with new code. Any testing that is started is liable to failbecause there will be an outage when end users are “flipped” from thefirst previously active side to the second previously passive side whenit flips to be active. However, the probability of any testing failingdiffers between each of these states and is also dependent on theestimated probability of successful completion of each of thetransitions from these states. This estimated probability may be basedon a past history of deployments on the side at which deployment istaking place. This will be described below in more detail with referenceto FIG. 7 .

Referring to FIG. 5 , which is a block diagram of an embodiment of asystem of forecasting future states of the multi-active cloud system.Production environment 502 is the environment that is providing aproduction service to end users. The production service is typically aservice provided by the production environment 502 through the cloud.Within production environment are shown two sides first side 504, andsecond side 506. These sides 504, 506 may be configured in a normaloperating configuration to either both be active at the same time orthey may be configured for one to be active and one to be passive. Ifthey are configured in a normal operating configuration to both beactive, then when a deployment of new code is planned, one of the sidesis changed from an active state to a passive state, the new code isdeployed to that side and then that side is made active again. If theyare configured in a normal operating configuration for one to be activeand one to be passive, then when a deployment of new code is planned,the new code is deployed to the side that is configured to be passive.The two sides are then flipped, so that the side that was passivebecomes active and the side that was passive becomes active.

Testing infrastructure 510 comprises the tests that are to be runagainst the production environment 502 during the Smoke Test describedabove. State Manager 520 manages the environment state 522. The stateswere explained above with reference to FIG. 4 . Each piece of state datatypically comprises:

{ “date”:“{current_timestamp}”, “cloud”:“{env_name}”,“server”:“{server_name}”, “side”:“{side_name}”,“state”:“{current_state}” }

Each piece of state data may further comprise additional items or mayomit any of the items specified, which are given as examples only.Control scripts 530 are used to control the process flow based on thestates and to set the states accordingly. Deploy 532 control scriptmoves a side 504, 506 from a Decommissioned state 402 into a Deployingstate 404 if the deployment is successful and potentially into a DeployFailed state 406 if the deployment is not successful. If the deploymentis successful, then the Deploy 532 control script passes control to theTest Inactive 536 control script. Flip 534 control script moves a sidethrough a Flipping state 412 state to an Available 416 state if the flipis successful or to a Flip Failed state 414 if the flip fails. TestInactive 536 control script is local to the state Smoke Test Runningstate 408. Depending upon preferences set, it may also be possible forthe Test Inactive 536 control script to be executed unconditionally inorder to see how severe a deployment failure is.

Referring to FIG. 6 , which is a data flow diagram showing data flows inan active/passive cloud system. Active/Passive cloud environment systems602-608 correspond to production environment 502 of FIG. 5 . Each of theActive/Passive cloud environment systems 602-608 have an active sidecorresponding to first side 504 of FIG. 5 and a passive sidecorresponding to second side 506 of FIG. 5 . Smoke tests 610 are carriedout on each of the cloud environments 602-608. The results of thosesmoke tests 610 are sent to a data aggregator 620, which aggregates thereceived smoke test result data. The data aggregator 620 is part of thestate manager 520 of FIG. 5 . The state manager 520 further comprises aforecasting model 630, which itself further comprises a componentweighting table 632 and data aggregation 634. Forecasting model 630 is aprediction model that predicts the probability of a flip. Componentweighting table 632 is used to weight the importance of any component indetermining when deciding if a flip should occur. The importance of oneserver when compared with another or of one smoke test when comparedwith another may be different. A failure of a database may be moresignificant to deciding whether a flip should occur than a failure of asingle application node from a cluster of application nodes in terms ofdetermining that a flip should not occur. Similarly, a failure of onesmoke test may be more significant in deciding whether a flip shouldoccur than a failure of another smoke test. Data aggregation 634receives data from many sources over time which is used by theforecasting model to make predictions of whether a flip should occur.

Referring to FIG. 7 , which is a flow diagram of an embodiment of amethod of forecasting future states of the multi-active cloud system ofFIG. 4 . An embodiment of a method according to the present inventionstarts at step 702. At step 704, a check is made as to the current stateof the side of the multi-active cloud system. If the state is“Deploying” 404, then processing proceeds to step 706. If the state is“Smoke Test Running” 408, then processing proceeds to step 714. If thestate is “Available” 416, then processing proceeds to step 722.Depending on the state of the side, different calculations are completedat steps 706 to 712, steps 714 to 720 or step 722. If the state is“Flipping” 412, then the Flip_Forecast is equal to 1 as a flip isdefinitely occurring and all testing should be paused. If the state isDecommissioned state 402, then the Flip_Forecast is equal to 0 as a flipcannot occur. These states are not shown in FIG. 7 , as there is nocalculation of a Flip_Forecast to be done, as it is possible to becertain that either there is a flip occurring or there will not be aflip.

If the state at step 704 was “Deploying” 404 and processing hasproceeded to step 706, then the current state rating per server isobtained. This is the current state of the server, that is “Deploying”,“Deployment failed” or “Deployment successful”. At step 708, theweighting rating per server is obtained. The weighting rating per serveris the importance of the server, that is, if the server failed, would itstill be possible to flip. At step 710, the deployment successprobability rating per server is obtained. The deployment success ratingis based on a server's current state and the importance of the server inthe overall system or side. These are used to generate a figure to beused by the final flip forecast logic. The figure represents theprobability of successful deployment of a side, but takes into accountthe importance of the server. The calculation of this figure may look athistorical data for the side as well. For example, if this side is oneside among many in a cluster, then have its siblings deployed correctlyin the past. At step 712, a flip forecast is calculated. Processingcontinues to step 724.

If the state at step 704 was “Smoke test running” 408 and processing hasproceeded to step 714, then the current state rating per smoke test isobtained. This is the current state of the smoke test, that is, is it inprogress, has it completed and, if so, was it successful. At step 716,the weighting rating per smoke test is obtained. The weighting ratingper server is the importance of the server, that is, if the serverfailed, would it still be possible to flip. At step 718, the successprobability rating per smoke test is obtained. The success probabilityrating is based on a test's current state and the importance of theserver in the overall system or side. These are used to generate afigure to be used by the final flip forecast logic. The figurerepresents the probability of this test returning successfully but takesinto account the importance of the test. The calculation of this figuremay look at historical data for the side as well. For example, whetherthe outcome of this smoke test is correlated to other smoke tests. Atstep 720, a flip forecast is calculated. Processing continues to step724.

If the state at step 704 was “Available” 416 and processing proceeded tostep 722, then the flip forecast value is set to zero as there is zerochance of the active side being flipped to become a passive side. Atthis step, it is assumed that the other side is decommissioned.Optionally, flips may be suppressed if automation is running on theactive side. Processing continues to step 724.

When step 724 is executed, either a flip forecast was calculated at step712 or step 720, or the flip forecast was set to zero at step 722. Atstep 724, a check is made as to whether the flip forecast is less than apre-determined value. In an embodiment, the pre-determined value is 0.8.In this embodiment, this means that a check is made as to whether thereis less than an 0.8 (or 80%) chance of a flip taking place. If the flipforecast is not less than 0.8, then a flip is quite likely to occur andprocessing proceeds to step 726. Values other than 0.8 may be used, theexact value to be used then being determined by experience. An exemplarycalculation of a flip forecast is described in the next paragraph. Atstep 726 a “DO NOT TEST” indication is provided meaning that it isadvised not to test the current side because a flip is likely to happen,causing an outage and the test to fail to complete. The embodiment ofthe method of the present invention ends at step 730. If the flipforecast is less than 0.8, then a flip is less likely to occur andprocessing proceeds to step 728. At step 728 a “TEST” indication isprovided meaning that it is advised that it is acceptable to test thecurrent side because a flip is not likely to happen, an outage isunlikely and the test will likely not fail to complete. The embodimentof the method of the present invention ends at step 730.

An exemplary calculation of a flip forecast will now be described. Thenumber of servers and all of the values used are exemplary only and areprovided solely in order to provide a clearer explanation of how a flipforecast is calculated.

In the exemplary calculation, it is assumed that there are threeservers, server A, server B and server C on one side. The followingvalues and the step in FIG. 7 where they are referred to may be, forexample:

Step 706—State rating values

-   -   Started=0.8    -   Success=1.0    -   Failed=0.3

Step 708—Weight rating values per server

-   -   Server A, weighting of 0.9    -   Server B, weighting of 0.7 (server B depends on server A)    -   Server C, weighting of 0.6 (server C depends on server C)

Step 710—Deployment success probability per server

-   -   Server A, 99% probability (has passed last three deployments)    -   Server B, 95% probability (has passed last two deployments,        failed one before)    -   Server C, 70% probability (has passed last deployment, failed        two before)

In the exemplary calculation, deployment of server A is in progress,deployment of server B is also in progress and deployment of server Chas been successfully completed. The probability of a particular servercompleting is calculated by multiplying the value for the state ratingby the value of the weight rating of the server and by the deploymentsuccess probability for the server. This gives the probability of thedeployment on the particular server being successful.

For server A, whose state is “started”, the state rating value is 0.8,the weight rating, based on past history is 0.9 and the deploymentsuccess probability is 0.99 as it has passed the last three deployments.Multiplying 0.8 by 0.9 and by 0.99 gives 0.7128, which corresponds to a71.28% chance of the deployment on server A being successful. Similarlyfor server B, the corresponding state rating, weight rating anddeployment success probability are 0.8, 0.7 and 0.95, giving 0.532,which corresponds to a 53.2% chance of the deployment on server B beingsuccessful. As server C has successfully deployed, the probability is 1,which corresponds to a 100% chance of the deployment on server C beingsuccessful. The state rating, weight rating and deployment successprobability given above are exemplary only and will vary for each serverbased on the past history of the server. Different initial values forthese rating may also be chosen before a history is available for theserver. The above are provided as examples only in order to assist inunderstanding embodiments of the invention.

The average value of the probability of the deployment on each of theparticular servers being successful is then calculated to give a totalflip forecast probability. Calculating the average for server A, serverB and server C above gives (0.7128+0.532+1)/3, which is 0.7483,corresponding to a 74.83% chance of a flip occurring. As 0.7483 is lessthan 0.8, the threshold value, a decision can be made to proceed withtesting on the active side as there is likely to be time to complete thetest before the flip is complete. Different numbers of servers ordifferent ways of combining together the probabilities may be used andthe method described above is exemplary only. The threshold value may be0.8 or it may be any other value, chosen based on experience of thevalue needed for a system to work optimally. The above are provided asexamples only in order to assist in understanding embodiments of theinvention.

A particular embodiment of the method shown in FIG. 7 is shown below inthe form of pseudo-code implementing the forecasting algorithm method ofFIG. 7 .

server_list = [‘serverA’,‘serverB’,serverC’] smoke_tests = [ ]flip_forecast = 0 if get_is_deploying( ) == True: flip_forecast_array =[ ] for server in server_list: # Value between 0 and 1 returned -Importance of 1 server_current_state = getCurrentStateRating(server) - #Value between 0 and 1 returned - Importance of 2 server_weighting =getWeightingRating(server) # Value between 0 and 1 returned - Importanceof 3 server_success_probability = getSuccessProbabilityRating(server)server_flip_forecast = calculate_server_forecast (server_current_state,server_weighting,server_success_probability )flip_forecast_array.add(server_flip_forecast) flip_forecast =calculate_forecast(flip_forecast_array) if get_is_smoke_testing( ) ==True: flip_forecase_array = [ ] for smoke_test in smoke_tests: # Valuebetween 0 and 1 returned - Importance of 1current_smoke_test_results_state = getCurrentSmokeTestRating(smoke_test)# Value between 0 and 1 returned - Importance of 2 smoke_test_weighting= getSuccessProbabilityRating(smoke_test) # Value between 0 and 1returned - Importance of 3 smoke_test_probability =getSmokeTestPassProbabilityRating(smoke_test) smoke_test_forecast =calculate_smoke_test_forecast( current_smoke_test_results_state ,smoke_test_weighting , smoke_test_probability ) flip_forecast_array.add(smoke_test_forecast ) flip_forecast = calculate_forecast(flip_forecast_array ) else: flip_forecast = 0 #Flip Forecast ifflip_forecast < 0.8: print ‘You can test’ else: print ‘Flip Pending, donot test’

The present invention may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instructions by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A method of managing two asynchronous workflowsin a computer system having at least an active server and a passiveserver, a first asynchronous workflow being for deployment of a codeupgrade on said passive server, a second asynchronous workflow being fortesting on said active server, the method comprising: determining anoperating state of the passive server, wherein the operating state ofthe passive server comprises one or more of a deploying state and asmoke testing state; identifying a state rating associated with thecurrent state of the passive server; identifying a deployment successprobability rating associated with the passive server; determining theprobability of the operating state successfully completing based atleast in part on the state rating and the deployment success probabilityrating; based on the probability of the operating state successfullycompleting exceeding a predetermined value, delaying the secondasynchronous workflow until the operating state successfully completes;and determining whether the passive server is in an available state andbased on a determination that the passive server is in the availablestate executing the second asynchronous workflow.
 2. The method of claim1, wherein delaying the second asynchronous workflow until the operatingstate successfully completes comprises determining if the probability ofthe operating state successfully completing is below a threshold value.3. A computer program product of managing two asynchronous workflows ina computer system having at least an active server and a passive server,a first asynchronous workflow being for deployment of a code upgrade onsaid passive server, a second asynchronous workflow being for testing onsaid active server, the computer program product comprising: one or morecomputer-readable storage media and program instructions stored on theone or more computer-readable storage media, the program instructionscomprising: program instructions to determine an operating state of thepassive server, wherein the operating state of the passive servercomprises one or more of a deploying state and a smoke testing state;program instructions to determine a rating associated with the passiveserver; program instructions to determine a deployment successprobability rating associated with the passive server; programinstructions to determine the probability of the operating statesuccessfully completing based at least in part on the rating and thedeployment success probability rating; based on the probability of theoperating state successfully completing exceeding a predetermined value,program instructions to delay the second asynchronous workflow until theoperating state successfully completes; and determining whether thepassive server is in an available state and based on a determinationthat the passive server is in the available state executing the secondasynchronous workflow.
 4. The computer program product of claim 3,wherein the program instructions to delay the second asynchronousworkflow until the operating state successfully completes comprisesprogram instructions to determine if the probability of the operatingstate successfully completing is below a threshold value.
 5. A computersystem for of managing two asynchronous workflows in a computer systemhaving at least an active server and a passive server, a firstasynchronous workflow being for deployment of a code upgrade on saidpassive server, a second asynchronous workflow being for testing on saidactive server, the computer system comprising: one or more processors,one or more computer-readable memories, one or more computer-readabletangible storage devices, and program instructions stored on at leastone of the one or more storage devices for execution by at least one ofthe one or more processors via at least one of the one or more memories,the program instructions comprising: program instructions to determinean operating state of the passive server, wherein the operating state ofthe passive server comprises one or more of a deploying state and asmoke testing state; program instructions to identify a state ratingassociated with the current state of the passive server; programinstructions to identify a weighted rating associated with the passiveserver; program instructions to determine the probability of theoperating state successfully completing based at least in part of thestate rating and the weighted rating; based on the probability of theoperating state successfully completing exceeding a predetermined value,program instructions to delay the second asynchronous workflow until theoperating state successfully completes; and determining whether thepassive server is in an available state and based on a determinationthat the passive server is in the available state executing the secondasynchronous workflow.